Pioneer 10 was a 20th-century NASA deep space probe which, in Star Trek V: The Final Frontier, is destroyed in 2287 by the bored Klingon captain Klaa as target practice.
Pioneer 10 was a real probe, launched by NASA in 1972 to fly past Jupiter and then leave the solar system. It carried a gold-anodised plaque showing a man and a woman and the position of the Sun, intended as a message for anyone who might find it.
The probe appears early in Star Trek V: The Final Frontier, drifting through space when a Klingon Bird-of-Prey decloaks beside it. Captain Klaa, complaining that shooting space debris is no test of a warrior, blows it to pieces from the gunner's chair.
Moments later his first officer Vixis brings word of the hostage crisis on Nimbus III and of the Enterprise's involvement, which gives Klaa the worthier opponent he wants, James Kirk.